1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * include/linux/pagevec.h
4  *
5  * In many places it is efficient to batch an operation up against multiple
6  * pages.  A pagevec is a multipage container which is used for that.
7  */
8 
9 #ifndef _LINUX_PAGEVEC_H
10 #define _LINUX_PAGEVEC_H
11 
12 /* 15 pointers + header align the pagevec structure to a power of two */
13 #define PAGEVEC_SIZE	15
14 
15 struct page;
16 struct address_space;
17 
18 struct pagevec {
19 	unsigned char nr;
20 	bool percpu_pvec_drained;
21 	struct page *pages[PAGEVEC_SIZE];
22 };
23 
24 void __pagevec_release(struct pagevec *pvec);
25 void __pagevec_lru_add(struct pagevec *pvec);
26 unsigned pagevec_lookup_entries(struct pagevec *pvec,
27 				struct address_space *mapping,
28 				pgoff_t start, unsigned nr_entries,
29 				pgoff_t *indices);
30 void pagevec_remove_exceptionals(struct pagevec *pvec);
31 unsigned pagevec_lookup_range(struct pagevec *pvec,
32 			      struct address_space *mapping,
33 			      pgoff_t *start, pgoff_t end);
pagevec_lookup(struct pagevec * pvec,struct address_space * mapping,pgoff_t * start)34 static inline unsigned pagevec_lookup(struct pagevec *pvec,
35 				      struct address_space *mapping,
36 				      pgoff_t *start)
37 {
38 	return pagevec_lookup_range(pvec, mapping, start, (pgoff_t)-1);
39 }
40 
41 unsigned pagevec_lookup_range_tag(struct pagevec *pvec,
42 		struct address_space *mapping, pgoff_t *index, pgoff_t end,
43 		int tag);
44 unsigned pagevec_lookup_range_nr_tag(struct pagevec *pvec,
45 		struct address_space *mapping, pgoff_t *index, pgoff_t end,
46 		int tag, unsigned max_pages);
pagevec_lookup_tag(struct pagevec * pvec,struct address_space * mapping,pgoff_t * index,int tag)47 static inline unsigned pagevec_lookup_tag(struct pagevec *pvec,
48 		struct address_space *mapping, pgoff_t *index, int tag)
49 {
50 	return pagevec_lookup_range_tag(pvec, mapping, index, (pgoff_t)-1, tag);
51 }
52 
pagevec_init(struct pagevec * pvec)53 static inline void pagevec_init(struct pagevec *pvec)
54 {
55 	pvec->nr = 0;
56 	pvec->percpu_pvec_drained = false;
57 }
58 
pagevec_reinit(struct pagevec * pvec)59 static inline void pagevec_reinit(struct pagevec *pvec)
60 {
61 	pvec->nr = 0;
62 }
63 
pagevec_count(struct pagevec * pvec)64 static inline unsigned pagevec_count(struct pagevec *pvec)
65 {
66 	return pvec->nr;
67 }
68 
pagevec_space(struct pagevec * pvec)69 static inline unsigned pagevec_space(struct pagevec *pvec)
70 {
71 	return PAGEVEC_SIZE - pvec->nr;
72 }
73 
74 /*
75  * Add a page to a pagevec.  Returns the number of slots still available.
76  */
pagevec_add(struct pagevec * pvec,struct page * page)77 static inline unsigned pagevec_add(struct pagevec *pvec, struct page *page)
78 {
79 	pvec->pages[pvec->nr++] = page;
80 	return pagevec_space(pvec);
81 }
82 
pagevec_release(struct pagevec * pvec)83 static inline void pagevec_release(struct pagevec *pvec)
84 {
85 	if (pagevec_count(pvec))
86 		__pagevec_release(pvec);
87 }
88 
89 #endif /* _LINUX_PAGEVEC_H */
90